Detent means for dater wheels

ABSTRACT

A SELF-CONTAINED DETENT MEANS FOR A SERIES OF TYPE WHEELS IS REMOVABLY SUPPORTED ON A COMMON SHAFT. UPON REMOVAL REPLACEMENT OF EACH WHEEL, THE DETENT THEREFOR REMAINS IN PLACE TO PREVENT LOSS OF THE DETENT AND TO FACILITATE EASY ASSEMBLY AND DISASSEMBLY OF THE APPARATUS.

D United States Patent 1 13,ss7,457

[72] In entor J h fl 484,389 1892 Bates 101/88 Cu y. Culif- 2,708,403 5/1955 Hanson et al 101/110 [21] Appl. No. 821,365 3,269,306 8/1966 Smllgys 101/110 {3:} E d 22 FOREIGN PATENTS atente une [73] Assign msin" cmpny 288,768 4/1928 Great Britain l0l/l 10 Primary Examiner-Robert E. Pulfrey Assistant Examiner-C. Coughenour [54] DETENT MEANS FOR DATER WHEELS Attorneys-Patrick J. Schlesinger, Charles R. Lepchinsky and 3 Claims, 2 Drawing Figs. Jay M Cantor [52] U.S.Cl l0l/ll0, 101/85, 74/527 [51] Int. Cl B4lj H54 [50] Field oISe-rch 101/106- 331741527 ABSTRACT: A self-contained detent means for a series of type wheels is removably supported on a common shaft. Upon [s6] cued removal and replacement of each wheel, the detent therefor UNn-ED STATES PATENTS remains in place to prevent loss of the detent and to facilitate 145.598 1873 Smith 101/85 easy assembly and disassembly of the apparatus.

DETENT MEANS FOR DATER WHEELS BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to printing apparatus utilizing type wheels rotatably supported on a shaft for adjustment to a value representative print position, or to a print position representative of a date. Thereafter, the wheels are yieldably retained in each adjusted position by means of spring detents.

2. Description of Prior Art In prior art devices, the detents are in the form of spring and balls, the balls being urged by compression springs into suitable notches in the inner periphery of a wheel. As a type wheel wears or it becomes desirable for other reasons to replace a wheel, the wheel is moved axially of its shaft and, unless considerable care is exercised, the detent ball is ejected, usually followed by the spring. Generally, both the ball and the spring are quite small and because of this fact, they easily become lost. Also, reassembly of the wheel, or shaft, becomes quite difficult, inasmuch as the spring must be held compressed by the ball as the wheel is moved into position axially of the shaft.

SUMMARY OF THE INVENTION By the use of the present invention, these prior art problems have been overcome. This invention relates to a printing device having a plurality of printing wheels supported for angular adjustment on a shaft in the framework of the device. Each printing wheel is selectively adjustable by a manually settable means. A pin for each printing wheel is diametrically disposed in the shaft'and yieldably retains each wheel in each adjusted position by means of a circular spring.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric projection of the dater print unit, showing the type wheels and setting mechanism therefor; and

FIG. 2 is an enlarged cross-sectional view of the type wheel and supporting shaft, showing the detent.

DESCRIPTION OF THE PREFERRED EMBODIMENT The invention is shown as, being embodied in a date wheel setting mechanism provided as a unit and secured within the framework of a postage meter of the type shown and described in U.S. Pat. No. 3,469,777 issued to Maynard E. Anderson et al. on Sept. 30, 1969. The date setting unit, as such, is supported in a manner such that the printing surface of the adjustable type wheels forms a part of the town circle die, which is usually adjacent, or is included in the postal indicia die plate..Also, the date setting wheels are made accessible to an operator for the adjustment of the type wheels.

Referring now to the drawings wherein like reference characters designate like or corresponding parts in the two FIGS., FIG. 1 shows that the date setting unit generally indicated at 10, comprises a substantially U-shaped frame 12, the legs 14 and 15 of which are provided with parallel lateral extensions, similar to extension 16 of leg 14. At the outer free end thereof, the extensions 16 support the respective ends of a shaft 17, upon which the month setting wheel 18, the tens day setting wheel 19, and the units day setting wheel 20 are adjustably mounted. The month setting wheel 18 includes an arcuate toothed rack 21 and a relatively wide arcuate flange 22, the peripheral surfaceof which bears the names of the months equiangularly spaced thereon. In addition to the months of the year, the peripheral surfaceof the flange 22 is also provided with a series of equiangularly spaced indentations 23, to enable an angular adjustment of the wheel. A similar arcuate rack of three teeth is formed on the tens day setting wheel 19, together with a diametrically opposed arcuate flange 24, which carries the numerals 1, 2 and 3, and a on the peripheral surface thereof. At each end of the arcuate flange 24 a radial projection 25 is provided for controlling adjustment of the wheel 19. The third, or units clay, setting wheel 20 carries a radially offset nine-tooth arcuate rack and diametrically-opposed thereto is an arcuate flange 31, having the numerals l to 9 and 0 equiangularly disposed on its outer surface. In order to control the angular adjustment of the wheel 20, a pin 32 projects laterally of the web of the wheel, adjacent the arcuate flange 31 and axially parallel with shaft 17.

The date line for the adjustment of the wheels 18, 19 and 20 is indicated by the end surfaces of the furcations 29 of a bifurcated lever, not shown, supported on a shaft 17 between wheels 18 and 19, and having its other end secured in the frame 12. As seen in FIG. 1, the date adjustment of the wheels is Jan. I l, which is the terminal counterclockwise rotated position of the three wheels, 18, 19 and 20. The limited rotation of each of setting wheels 18 and .20 in each direction is determined by a pair of pins similar to pins 33 and 34, secured on the web of wheel 20 for engagement with the corresponding extension 16 of the frame 12.

As each of the setting wheels l8, l9 and 20 is adjusted to represent a date, a like adjustment is respectively imparted to a month type wheel 35, a tens day type wheel 36 and a units day type wheel 37. For this purpose, the teeth of the rack portion of each setting wheel 1'8, 19 and 20 is enmeshed with respective intermediate pinions 38, 39 and 40, rotatably supported on a shaft 41, secured at its ends in the legs 14 and 15 of frame 12. Pinion 38, in turn, is enmeshed with gear teeth 42, forming one-half the surface width of the type wheel 35. The three-letter representation for each of the 12 months is embossed on the full surface width of the type wheel 35 axially thereof. Each of the pinions 39 and 40 are enmeshed with respective type wheels 36 and 37, which are in the form of gears having the numerals embossed upon thetop surface of the teeth of the wheels. Each of the year type wheels 45 and 46 is similar in form to that of type wheel 37, having the type characters, or numerals, embossed on the top surface of the teeth of each wheel. Inasmuch as either or both of type wheels 45 and 46 is only changed once a year, a stylus may be used for this purpose, by insertion into the tooth spaces of each wheel.

Although pins 33 and 34-of each of the setting wheels 18 and 20 serve to limit rotation of the corresponding wheels in either direction, other meansare also provided which serve to ensure that each of the setting wheels l8, l9 and 20 do not become out of phase with the respective type wheels 35, 36 and 37. Upon movement of any one of the setting wheels 18, 19 and 20 to either extreme position, the broad half teeth at each end of the respective racks, similar to the half teeth 47 or 48 of wheel 20, become effective to prevent counter rotation of the respective pinions 38, 39 or 40. For example, as seen in FIG. 1, setting wheel 20 is in the extreme counterclockwise rocked position, wherein a tooth of the: corresponding pinion 40 engages the broad tooth 48 of the wheel, thereby preventing further clockwise rotation of the pinion and, in addition to the engagement of the pin 33 in the wheel 20 with the extension 16, blocks the wheel 20 against further rotation in a counterclockwise direction.

Each of the type wheels 35, 36 and 37, as well as year type wheels 45 and 46 are supported for rotation on a shaft 50. Shaft 50 is nonrotatably secured in place between the legs 14 and 15 of frame 12 by means of a pair of pins 51 (FIG. 2) extending lengthwise of the shaft 50 in suitable axially parallel bores within the shaft. Within the inner surface of each of the type wheels 35, 36, 37, 45 and 46 are: a series of V-shaped notches 52, axially disposed and equiangularly spaced .in accordance with the spacing'of'the teeth of each type wheel (FIG. 2).

Upon the selective adjustment of each type wheel 35, 36, 37, 45 and 46, means become effective to resiliently retain each wheel in its adjusted position. To this end, a channel 53 having chamfered sidewalls, extends longitudinally of the shaft, with its flat bottom portion parallel to the axis of the shaft. A series of annular grooves 54, Le, one for each of the type wheels, are formed along the shaft 50 eccentric relative to the axis of the shaft with the major depth of the groove occurring at the intersection of the groove with the longitudinal channel 53. The grooves 54 are spaced axially of the shaft 50 such that each groove is disposed in accordance with the circumferential center line of the corresponding type wheel. A series of parallel diametral bores 55 are formed in the shaft 50, one such bore 55 for each annular groove 54. At its one end, each bore 55 opens into the flat bottom surface of the channel 53, while the other, or lower, end of each bore 55 opens into the shallowest portion of the corresponding eccentrically fonned groove 54.

Positioned within each bore 55 is a pin 56, the lower surface of the round head portion 57 of which normally rests against the bottom surface of the channel 53. At its lower end, each pin 56 is tapered and is adapted to be yieldably maintained by means of a sigmoidal or C-shaped spring 58 in a Vshaped notch 52 in each adjusted position of the corresponding type wheel. A spring 58 is disposed in each annular groove 54 and engages the round head 57 of the corresponding pin 56, normally urging the pin downwardly, as seen in FIG. 2, to engage the tapered end in a V-notch 52. Each of the springs 58 is open in the area at the point of intersection of the respective pins 56 with the corresponding annular grooves 54.

Thus, it can be seen that, as each type wheel is rotated, the associated pin 56 is moved upwardly (FIG. 2) against the urgency of the corresponding spring 58. As a printing wheel is angularly rotated from one position to another, each angular step of rotation of the wheel causes the associated pin 56 to be moved upwardly in FIG. 2. During the rotation of a wheel and as each type character moves into print position, the tapered end of the associated pin 56 engages in the corresponding notch 52 of the wheel under the influence of the associated spring 58.

it can also be seen that any one or more of the type wheels 35, 36, 37, 45 or 46 may be axially removed from the shaft, or replaced on the shaft, without displacement of the corresponding detent pin 56. As a printing, or type, wheel is removed from the shaft 50, the associated spring 58 retains the corresponding pin 56 in the shaft 50. The pin cannot fall out or be ejected as in the case of a prior art spring and ball detent.

I claim:

1. In a printing device:

a framework;

a shaft secured in said framework;

a plurality of printing wheels mounted for angular adjustment on said shaft; each of said wheels having a plurality of indentations formed in the inner peripheral surface thereof, one indentation for each angularly adjusted position of said wheels;

manually operable means for selectively adjusting each of said wheels;

said shaft including a plurality of apertures extending therethrough and spaced axially of said shaft in accordance with the axial spacing of said wheels;

a series of pins, one for each of said printing wheels movable endwise in said apertures in said shaft;

' each of said pins having a head portion formed at its one end and a taper at its other end for engagement in said indentations in a corresponding wheel; and

a resilient means normally operable to retain said pins in said shaft and to yieldably maintain said pins in said indentations.

2. In a device of the character described in claim 1 wherein:

said shaft is formed with a channel extending longitudinally thereof intersecting said apertures and adapted to receive the head portion of each of said pins; and

a plurality of eccentric annular grooves in said shaft, one for each of said printing wheels, intersecting said channel and each corresponding aperture and adapted to confine said resilient means axially of said shaft.

3. In a device of the character described in claim 2 wherein said resilient means is a sigmoidally shaped spring disposed in each of said annular grooves operable to resilientl retain said pins in the apertures in said shaft, the tapered en of said pins normally projecting through the opening in said spring 

